Fuel containing anti-icing additive



United States Patent 3,219,424 FUEL CONTAINING ANTI-ICING ADDITIVE Everett N. Case, Homewood, and Robert Koncos, Park Forest, 11]., assignors to Sinclair Research, Inc., Wilmington, Del., a corporation of Delaware No Drawing. Filed Oct. 6, 1961, Ser. No. 143,296 6 Claims. (Cl. 44-63) attached to a C atom or atoms in the ring. They may correspond to the structural formula where R is H, a fused ring aromatic, or an alkyl radical, for instance, a lower alkyl radical such as methyl, ethyl, butyl, amyl and isoamyl radicals. The invention also contemplates as the cyclic amine oxide, quinoline-N- oxide. Thus the carbon atoms in the pyridine-N-oxide can be substituted or used in a fused ring relationship although the basic pyridine-N-oxide structure remains and characterizes the compounds. The cyclic amine oxides include picoline oxide e.g. Z-picoIine-N-oxide, pyridine oxide, parvoline-N-oxide, conyrine-N-oxide, collidine-N- oxide, and lutidine-N-oxide e.g. fl-lutidine-N-oxide.

The cyclic amine oxide can be utilized in gasoline fuels, i.e., hydrocarbon mixtures boiling in the gasoline range, in concentrations that are sufficient to reduce the spark ignition engine stalling tendencies of these fuels. The cyclic amine oxide is particularly desirable for use in this connection since it is economically advantageous on a cost basis, and exhibits advantageous anti-stalling characteristics when employed in minimal amounts. The cyclic amine oxide is generally employed in gasoline in concentrations of from about 0.0001 to 0.5 or more volume percent and preferably from about .004 to 0.05 volume percent.

With respect to the particular concentration ranges mentioned above, it will be appreciated that the optimum concentration of the anti-stalling additive can vary according to the severity of the atmospheric conditions. With regard to this factor, the problem of engine stalling due to carburetor icing resulting from the refrigeration of moisture condensed from the atmosphere by evaporating gasoline has been observed to be significant at atmospheric temperatures of between about 30 and 60 F. and when the relative humidity is in excess of about 65 percent. The concentration of anti-stalling additive should be suflicient to effect a substantial reduction in the stalling tendencies of the fuel at the atmospheric conditions of temperature and humidity which are likely to be encountered in service.

The problem of engine stalling due to carburetor icing during rapid evaporation of gasoline occurs primarily in connection with gasolines having a relatively low 50 percent ASTM distillation point of not greater than about 3,219,424 Patented Nov. 23, 1965 "ice 275 F. While occasional engine stalling may occur as a result of carburetor icing at severe atmospheric conditions of temperature and humidity with gasolines having somewhat higher 50 percent ASTM distillation points, experience has indicated that the problem does not normally assume such significant magnitude. Preferably, the gasoline includes liquid hydrocarbon mixtures having a 90 percent ASTM distillation point of not more than about 395 F. and a 10 percent ASTM distillation point of not more than about 140.

The anti-stalling additives included in the composition of this invention can be incorporated into gasoline compositions in any convenient manner. If desired, the cyclic amine oxides can be added in the form of concentrated solutions or dispersions in solvents such as mineral oil, gasoline, naphtha, Stoddard solvent, mineral spirits, benzene, heptane, kerosene or the like. If desired, the anti-stalling agent can be incorporated in gasoline fuel compositions in admixture with other gasoline improvement agents, such as antioxidants, anti-knock agents, ignition control additives, dehazing agents, anti-rust additives, dyes and the like.

The novel compositions of this invention are illustrated with the following specific examples.

EXAMPLE I Z-picoIine-N-oxide was incorporated into a gasoline fuel described in Table I below, in an amount of 0.005 volume percent to provide a gasoline composition with advantageous anti-stalling characteristics.

The composition was evaluated by the Briggs and Stratton, single cylinder, four stroke cycle engine anti-icing screening test. The composition gave 60 seconds of engine operation before appearances of frost on the throttle plate. Essentially the same gasoline, described in Table I below, without the 2-picoline-N-oxide, only gave about 42 seconds of engine operation before the appearance of frost on the throttle plate.

Table I LABORATORY INSPECTIONS ON TEST FUEL Composition:

Naphtha reformate peroent 39.6 Light catalytically cracked gasoline do 52.6 n-Butane do 7.8 Gravity, API 56.3 100 cc. dist.:

IBP 89 5 104 10 113 20 132 30 154 40 182 50 221 60 274 70 315 329 345 370 EP 400 Percent recovery 97.0 Percent loss 2.0 Percent parafiins 28.5 Percent olefins 39.7 Percent naphthenes 0.0 Percent aromatics 31.8 Bromine No. 62.0

EXAMPLE II The Briggs and Stratton, single cylinder, 4 stroke cycle engine anti-icing test employed in Example I is conducted as follows:

The conventional Briggs and Stratton carburetor is replaced with a short section of double walled glass tubing containing a throttle plate held in fixed position in order to permit ready observance of incipient throttle plate frosting. A venturi installed ahead of the plate provides means for mixing of the fuel and air. The engine is run unloaded at a speed of 3200 r.p.m. plus 50 r.p.m. The intake air is passed through an ice tower to efiect control of temperature and humidity prior to mixing of the fuel. The temperature will range between 46 to 48 F. and the relative humidity between 94% and 96%. Fuel is drawn into the induction system through a hypodermic needle (0.018" diam.) located in the venturi throat. Fuel to this orifice is supplied from either of two glass bottles of 4 ounce capacity connected together by suitable valving. The small differential between atmospheric pressure and venturi pressure is sufiicient to force the fuel into the venturi for mixing with air.

The throttle plate, located 1 /2 inches downstream from the venturi consists of a perforated brass disk set at a 45 angle in the manifold. Spring clips soldered to the plate hold it in place. The clearance space between the induction tube and the throttle plate is approximately The measure of additive eifectiveness is the difference in time as measured in seconds required for just visible frosting of the throttle plate compared with the time required for frost formation on the same fuel containing an additive.

Quinoline-N-oxide is substituted for the 2-picoline-N- oxide of Example I to provide a gasoline composition with anti-stalling characteristics.

It is claimed:

1. A normally liquid hydrocarbon gasoline having incorporated therein an anti-stalling amount of a gasolinesoluble, water-dispersible, cyclic amine oxide having the structural formula where R is selected from the group consisting of hydrogen and a lower alkyl radical.

2. The composition of claim 1 wherein the fuel is gasoline and the anti-stalling amount is from about 0.0001 to 0.5 volume percent.

3. The gasoline of claim 1 wherein 1 to 3 of the R groups are lower alkyl radicals of 1 to 5 carbon atoms and the remainder of the R groups are hydrogens.

4. The gasoline of claim 1 having a percent ASTM distillation point not greater than about 395 F. and a 10 percent ASTM distillation point not greater than about F.

5. The composition of claim 4 wherein the cyclic amine oxide is 2-picoline-N-oxide.

6. A normally liquid hydrocarbon gasoline having incorporated therein an anti-stalling amount of gasolinesoluble, water-dispersible quinoline-N-oxide.

References Cited by the Examiner UNITED STATES PATENTS 1/1960 Carr 44-63 4/1961 Becker 4463 

1. A NORMALLY LIQUID HYDROCARBON GASOLINE HAVING INCORPORATED THEREIN AN ANTI-STALLING AMOUNT OF A GASOLINESOLUBLE, WATER-DISPERSIBLE, CYCLIC AMINE OXIDE HAVING THE STRUCTURAL FORMULA 